| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrafine polyester fiber with a single fiber fineness of 1.0 dtex or less, capable of coloring excellent in deep color property and fastness in the coloring under the ordinary pressure environment and having stable quality and processability.SOLUTION: In the sea-island conjugate fiber, a sea component contains a water-soluble polyvinyl alcohol-based polymer and island component contains a polyester resin showing a deep color to a cationic dye and a disperse dye. The polyester resin in the island component is a copolymer polyester consisting of a dicarboxylic acid component and a glycol component and has at least three or more copolymerization components, 75 mol% or more of the dicarboxylic acid component in the polyester resin is terephthalic acid and/or ester formative derivatives thereof and the copolymerization component contains (A) isophthalic acid quaternary phosphonium salt or quaternary ammonium salt, (B) cyclohexanedicarboxylic acid and/or ester formative derivatives thereof and (C) aliphatic dicarboxylic acid and ester formative derivatives thereof. |
